ahaggarty
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 posted on 20/3/15 at 01:28 PM |
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Engine Overheating
I haven't been on here for while. Last time, I had a problem with my 1600 kent crossflow overheating badly. After deciding to completely
recondition my Locost 7 I removed the engine and found the cause. A core plug had gone, the large one at the rear end underneath the gearbox cowling.
I suspected this when I saw a slight drip coming from underneath around this area. I found some of the water ways quite clogged up with rust so had to
dig them all out to improve flow etc.
I have had the block rebored to +40 thou, new pistons, crank reground, new shell bearings, then had the whole lot balanced including lightening the
flywheel.
I'm switching to twin choke 40's and a freeflow exhaust manifold, electronic ignition and vernier pulley, fast road camshaft.
I am currently having a dilemma over what to do with the cylinder head? I want to gas flow and use bigger valves but also to have hardened seats
fitted so I can use unleaded petrol. I'm wondering whether to switch to an alloy head or stick with the cast iron one? Alloy heads are so
expensive, around £1000 to buy with that spec. Is the expense worth it??
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Paul Turner
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| posted on 20/3/15 at 01:41 PM |
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Unless you need a x-flow for a specific racing championship replace it with a modern engine.
I love x-flows but spending huge money on one to get perhaps 160 untractable bhp when a £700 brand new crate Zetec will give 175 tractable bhp out of
the box just does not make sense.
Think again before you spend.
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ahaggarty
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| posted on 20/3/15 at 03:18 PM |
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Yes I see what you mean. However once Ive built that engine up to fast road spec it will be worth far more than £750 and probably far less to go wrong
with it than on a modern day engine. It might be something to consider in the future but for now I'm sticking with the old school!
What did you mean by untractable? Thye wheels will spin bu the car wont move? Or the gearing will make it difficult?
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19sac65
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| posted on 20/3/15 at 05:21 PM |
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Once you start upping the compression,fitting peaky cams etc the powers up but sits higher up the rev band
Low down torque and lumpiness is the trade off
So for track its fine as your thrashing it but everyday road use it can get tiresome
I opted for the zetec
As said more power out of the box ,more torque , a nice smooth even spread all the way up and all from a standard engine so its not stressed
The difference is night and day, completely transformed the car
A modern 16v twin cam engine is far superior
In my humble opinion of course
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cliftyhanger
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| posted on 20/3/15 at 05:45 PM |
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Just keep the std cast one. Ask teh cam supplier what CR it should be running or what chamber volume you need, and then get the head worked or at
least skim to suit.
Modern engines are not complicated, strip off off the management stuff, and they are barely different to an old engine. It is just they are better
designed from the beginning. But here, just stick with what you know/want. As an aside, I have had reground cams not last long (kent cam I think) in
OHV engines, and general issues with poor quality in reproduction parts. However, I suspect there is some very good crossflow stuff available (but I
bet some dross too)
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02GF74
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| posted on 20/3/15 at 09:38 PM |
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I dont think the alloy head @1000 is worth it.... and i thought that was the bare head, machining to gas fkow and valves were extra?
Flowed head , hardened seats and larger inlet and exhaust valve head were around £ 350 a few years back, save the £700 for something else. eg vernier
timing gear, megasquirt, TBs, megajiolt, suspension, lighter wheeks, wilwood callipers etc
Skimming head wont raise cr unless you have the earlier chambered head. (Btw i have one of these with huge ports FS).
Std practise was to fit 1300 pistos to increase cr.
... and yes it is far more cost effective to go zetec, i considered it but would have had to raise the bonnet which woukd have spoilt looks.
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David Jenkins
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| posted on 20/3/15 at 10:11 PM |
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quote:
Originally posted by Paul Turner
Unless you need a x-flow for a specific racing championship replace it with a modern engine.
I love x-flows but spending huge money on one to get perhaps 160 untractable bhp when a £700 brand new crate Zetec will give 175 tractable bhp out of
the box just does not make sense.
Think again before you spend.
I totally agree - to a point. I have a x-flow in my car and I love it, but if it goes seriously wrong then I won't spend money on fixing it and
will probably replace it with a Zetec. However, the Zetec is much taller than the x-flow and replacing one with the other isn't that easy in a
Locost. In the past the Toyota 4-AGE engine was a good replacement as that was quite a short engine, but they're quite scarce these days. You
also have the problem of fitting it to a Type 9 gearbox with a special bell-housing, which ain't cheap. Of course, connecting a Zetec to a Type
9 is a doddle!
None of the problems of fitting in a Zetec are insurmountable - many have done it, after all - but it's not a one-for-one replacement.
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Paul Turner
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| posted on 21/3/15 at 08:18 AM |
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quote:
Originally posted by David JenkinsHowever, the Zetec is much taller than the x-flow and replacing one with the other isn't that
easy in a Locost.
Mine is in a Caterham and space is equally tight but it is doable. There is literally mm's between the sump and chassis when fitting it.
Originally I had a Silvertop in mine and I was able to retain the cam belt covers which was actually touching the underside of the nose. But when I
swapped to a Blacktop the belt covers had to go, just too tall. I also retained the Silvertop cam cover which is slightly lower. To get the 75mm min
ground clearance the car did need raising a little but at the time I did it I needed new tyres so I simply a set of 14" wheels I had instead of
the previous 13" wheels which sorted that without messing the suspension geometry.
quote:
Originally posted by David JenkinsOf course, connecting a Zetec to a Type 9 is a doddle!
The important thing is to ensure you have the correct release bearing for your clutch/flywheel combination.
quote:
Originally posted by David Jenkins
None of the problems of fitting in a Zetec are insurmountable - many have done it, after all - but it's not a one-for-one replacement.
I got all the bits together over about a year and the engine prepared. Started removing the x-flow Saturday morning first thing and by 2.00 pm the
same day the car was sat with a Zetec bolted in it, we even had a break for fish and chips.
Fit new manifold, carbs of x-flow, Weber ECU and underbonnet loom and the new cooling pipes and it started first time.
I did not find it any more difficult than fitting a x-flow for the first time.
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ahaggarty
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| posted on 8/4/15 at 12:22 PM |
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Dear All, Thanks for allyour replys/comments they have all given me a lot of food for thought! I will have to stick with what I have got for now and
see the project through to the end with the crossflow but in the future I like the sound of the Zetec.
The point about staying with the cast head against spending out for the alloy makes sense as I probably wouldnt notice the weight difference between
the two anyway?
I have an issue with the speedo cable where it goes into the gearbox. Basically as the cable comes out straight it has been fouling on part of the
underbody and become so distressed it stopped working so I need to replace it. Can I get one with a 90 degree fitting instead of straight so as it
comes out of the type 9 gearbox it turns at 90 so doesnt foul the underbody?
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Paul Turner
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| posted on 8/4/15 at 02:02 PM |
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quote:
Originally posted by ahaggartyI have an issue with the speedo cable where it goes into the gearbox. Basically as the cable comes out
straight it has been fouling on part of the underbody and become so distressed it stopped working so I need to replace it. Can I get one with a 90
degree fitting instead of straight so as it comes out of the type 9 gearbox it turns at 90 so doesnt foul the underbody?
This is what you need.
http://www.speedograph-richfield.com/html/rgb1030.html
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ahaggarty
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 posted on 9/4/15 at 12:09 PM |
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Cheers Paul.
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